Predictive factors for the efficacy of switch to oral hypoglycemic agents in Japanese type 2 diabetic patients with intensive insulin therapy temporarily introduced.

Some type 2 diabetic patients can maintain optimal glycemic control by oral hypoglycemic agents (OHA) after their uncontrolled hyperglycemia is corrected by a temporary introduction of insulin therapy. The objective of this study was to investigate the clinical predictors for the efficacy of OHA after intensive insulin therapy was temporarily introduced. We analyzed a retrospective database of 108 Japanese type 2 diabetic patients who underwent a 75-g oral glucose tolerance test (OGTT) after the temporary introduction of intensive insulin therapy, and tried the switch to OHA. The multivariate logistic regression analysis revealed that shorter diabetic duration, higher body mass index, and lower 2-h post meal glucose levels were independently associated with the efficacy of OHA (all p < 0.001). The C statistic of the multivariate model was calculated to be 0.86. The addition of 120-min insulinogenic index, calculated from 0-, 30-, 60-, and 120-min data during an OGTT, to the model significantly increased the C statistic to 0.91 (p = 0.025). Interestingly, omitting 30- and 60-min data from the calculation of the index did not reduce the predictive performance. Furthermore, the ratio of 120-min insulin levels to 120-min glucose levels also provided a comparable predictive performance. In conclusion, 0- and 120-min data during an OGTT, or even 120-min data alone, in combination with diabetic duration, body mass index, and 2-h post meal glucose levels were useful in predicting the efficacy of OHA after intensive insulin therapy in Japanese type 2 diabetic patients.